I have a serious weakness for the Australian tree fern. Although there are many tree ferns found in cultivation, this is the most common and, arguably, the most beautiful. Native to tropical and subtropical forests, tree ferns thrive in high humidity and partial shade. In nature, these ferns can grow up to 50 feet, with massive light-green fronds up to 20 feet, but this kind of growth is only possible in cultivation in a greenhouse or conservatory. In fact, these are somewhat demanding and fussy plants that often succumb to less-then-ideal conditions. But while they're thriving, they are wonderful large ferns.
Light: Dappled sunlight or shade. Do not expose to direct sunlight. They can handle stronger sun in more northern latitudes.
Water: Even, regular and copious moisture and high humidity. Never allow to dry out.
Temperature: They reportedly can survive light frosts, down to 25ºF. However, they don't appreciate sudden fluctuations in temperature, and hot, dry conditions are fatal.
Soil: Rich, very well-drained organic material.
Fertilizer: Heavy feeders. Use slow-release pellets three times annually.
By spore. Propagation is best left to professionals, unless you're familiar with fern reproduction.
The Australian tree ferns is Cyathea cooperi, but is sometimes offered as Alsophila cooperi or Sphaeropteris cooperi. There are several other tree ferns found in cultivation, such as the Mexican tree fern (Cibotium schiedei), but these are unrelated to the C. cooperi.
Native to Australian and New Zealand, tree ferns are often found growing on misty mountainsides in great profusion. In the indoor environment, the key to success to is to provide very wet and humid, but mild, conditions. They dislike extreme heat and cannot tolerate dry air or compost. Finally, they are very heavy feeders and will thrive with frequent applications of fertilizer. Trim off dead bottom fronds and protect the central growth point, where new fronds rise in graceful, curling arches.